Electronic devices such as laptop computers, cellular telephones, and other equipment are sometimes provided with light sensors. For example, ambient light sensors may be incorporated into a device to provide the device with information on current lighting conditions. Ambient light readings may be used in controlling an electronic device. For example, ambient light color measurements can be used in adjusting the color cast of a display. When lighting conditions are cool, the white point of a display can be adjusted to a cooler value and when lighting conditions are warm, the white point of the display can be adjusted to a warmer value. These adjustments may help maintain a pleasing appearance for images on a display as ambient light changes color.